[1/4] Add vector pair modes to PowerPC (patch attached)

Message ID ZVrfJWSMWzTwLWDu@cowardly-lion.the-meissners.org
State Unresolved
Headers
Series Add vector pair support to PowerPC attribute((vector_size(32))) |

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Commit Message

Michael Meissner Nov. 20, 2023, 4:23 a.m. UTC
  (sorry I just posted the ChangeLog entry and not the patch).

We have had several users ask us to implement ways of using the Power10 load
vector pair and store vector pair instructions to give their code a speed up
due to reduced memory bandwidth.

I had originally posted the following patches:

    *	https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636077.html
    *	https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636078.html
    *	https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636083.html
    *	https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636080.html
    *	https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636081.html

to add a set of built-in functions that use the PowePC __vector_pair type and
that provide a set of functions to do basic operations on vector pair.

After I posted these patches, it was decided that it would be better to have a
new type that is used rather than a bunch of new built-in functions.  Within
the GCC context, the best way to add this support is to extend the vector modes
so that V4DFmode, V8SFmode, V4DImode, V8SImode, V16HImode, and V32QImode are
used.

While in theory you could add a whole new type that isn't a larger size vector,
my experience with IEEE 128-bit floating point is that GCC really doesn't like
2 modes that are the same size but have different implementations (such as we
see with IEEE 128-bit floating point and IBM double-double 128-bit floating
point).  So I did not consider adding a new mode for using with vector pairs.

My original intention was to just implement V4DFmode and V8SFmode, since the
primary users asking for vector pair support are people implementing the high
end math libraries like Eigen and Blas.

However in implementing this code, I discovered that we will need integer
vector pair support as well as floating point vector pair.  The integer modes
and types are needed to properly implement byte shuffling and vector
comparisons which need integer vector pairs.

With the current patches, vector pair support is not enabled by default.  The
main reason is I have not implemented the support for byte shuffling which
various tests depend on.

I would also like to implement overloads for the vector built-in functions like
vec_add, vec_sum, etc. that if you give it a vector pair, it would handle it
just like if you give a vector type.

In addition, once the various bugs are addressed, I would then implement the
support so that automatic vectorization would consider using vector pairs
instead of vectors.

This is the first patch in the series.  It implements the basic modes, and
it allows for initialization of the modes.  I've added some optimizations for
extracting and setting fields within the vector pair.

The second patch will implement the floating point vector pair support.

The third patch will implement the integer vector pair support.

The fourth patch will provide new tests to the test suite.

When I test a saxpy type loop (a[i] += (b[i] * c[i])), I generally see a 10%
improvement over either auto-factorization, or just using the vector types.

I have tested these patches on a little endian power10 system.  With
-vector-size-32 disabled by default, there are no regressions in the
test suite.

I have also built and run the tests on both little endian power9 and big
endian power9 systems, and there are no regressions.  Can I check these
patches into the master branch?

2023-11-19  Michael Meissner  <meissner@linux.ibm.com>

gcc/

	* config/rs6000/constraint.md (eV): New constraint.
	* config/rs6000/predicates.md (cons_0_to_31_operand): New predicate.
	(easy_vector_constant): Add support for vector pair constants.
	(easy_vector_pair_constant): New predicate.
	(mam_assemble_input_operand): Allow other 16-byte vector modes than
	Immodest.
	* config/rs6000/rs6000-c.cc (rs6000_cpu_cpp_builtins): Define
	__VECTOR_SIZE_32__ if -mvector-size-32.
	* config/rs6000/rs6000-protos.h (vector_pair_to_vector_mode): New
	declaration.
	(split_vector_pair_constant): Likewise.
	(rs6000_expand_vector_pair_init): Likewise.
	* config/rs6000/rs6000.cc (rs6000_hard_regno_mode_ok_uncached): Use
	VECTOR_PAIR_MODE instead of comparing mode to OOmode.
	(rs6000_modes_tieable_p): Allow various vector pair modes to pair with
	each other.  Allow 16-byte vectors to pair with vector pair modes.
	(rs6000_setup_reg_addr_masks): Use VECTOR_PAIR_MODE instead of comparing
	mode to OOmode.
	(rs6000_init_hard_regno_mode_ok): Setup vector pair mode basic type
	information and reload handlers.
	(rs6000_option_override_internal): Warn if -mvector-pair-32 is used
	without -mcpu=power10 or -mmma.
	(vector_pair_to_vector_mode): New function.
	(split_vector_pair_constant): Likewise.
	(rs6000_expand_vector_pair_init): Likewise.
	(reg_offset_addressing_ok_p): Add support for vector pair modes.
	(rs6000_emit_move): Likewise.
	(rs6000_preferred_reload_class): Likewise.
	(altivec_expand_vec_perm_le): Likewise.
	(rs6000_opt_vars): Add -mvector-size-32 switch.
	(rs6000_split_multireg_move): Add support for vector pair modes.
	* config/rs6000/rs6000.h (VECTOR_PAIR_MODE): New macro.
	* config/rs6000/rs6000.md (wd mode attribute): Add vector pair modes.
	(RELOAD mode iterator): Likewise.
	(toplevel): Include vector-pair.md.
	* config/rs6000/rs6000.opt (-mvector-size-32): New option.
	* config/rs6000/vector-pair.md: New file.
	* doc/md.texi (PowerPC constraints): Document the eV constraint.
---
 gcc/config/rs6000/constraints.md  |   6 +
 gcc/config/rs6000/predicates.md   |  32 ++-
 gcc/config/rs6000/rs6000-c.cc     |   3 +
 gcc/config/rs6000/rs6000-protos.h |   3 +
 gcc/config/rs6000/rs6000.cc       | 294 +++++++++++++++++++++++++--
 gcc/config/rs6000/rs6000.h        |   6 +
 gcc/config/rs6000/rs6000.md       |   7 +-
 gcc/config/rs6000/rs6000.opt      |   4 +
 gcc/config/rs6000/vector-pair.md  | 319 ++++++++++++++++++++++++++++++
 gcc/doc/md.texi                   |   4 +
 10 files changed, 656 insertions(+), 22 deletions(-)
 create mode 100644 gcc/config/rs6000/vector-pair.md
  

Patch

diff --git a/gcc/config/rs6000/constraints.md b/gcc/config/rs6000/constraints.md
index c4a6ccf4efb..f28e7701a4e 100644
--- a/gcc/config/rs6000/constraints.md
+++ b/gcc/config/rs6000/constraints.md
@@ -219,6 +219,12 @@  (define_constraint "eQ"
   "An IEEE 128-bit constant that can be loaded into VSX registers."
   (match_operand 0 "easy_vector_constant_ieee128"))
 
+;; A vector pair constant that can be loaded into registers without using a
+;; load operation.
+(define_constraint "eV"
+  "A vector pair constant that can be loaded into VSX registers."
+  (match_operand 0 "easy_vector_pair_constant"))
+
 ;; Floating-point constraints.  These two are defined so that insn
 ;; length attributes can be calculated exactly.
 
diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md
index ef7d3f214c4..1a1ebfd0e72 100644
--- a/gcc/config/rs6000/predicates.md
+++ b/gcc/config/rs6000/predicates.md
@@ -327,6 +327,11 @@  (define_predicate "const_0_to_15_operand"
   (and (match_code "const_int")
        (match_test "IN_RANGE (INTVAL (op), 0, 15)")))
 
+;; Match op = 0..31
+(define_predicate "const_0_to_31_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), 0, 31)")))
+
 ;; Return 1 if op is a 34-bit constant integer.
 (define_predicate "cint34_operand"
   (match_code "const_int")
@@ -729,6 +734,9 @@  (define_predicate "easy_vector_constant"
       if (zero_constant (op, mode) || all_ones_constant (op, mode))
 	return true;
 
+      if (VECTOR_PAIR_MODE (mode) && easy_vector_pair_constant (op, mode))
+	return true;
+
       /* Constants that can be generated with ISA 3.1 instructions are
          easy.  */
       vec_const_128bit_type vsx_const;
@@ -759,6 +767,26 @@  (define_predicate "easy_vector_constant"
   return false;
 })
 
+;; Return 1 if the operand is a CONST_VECTOR and can be loaded into a
+;; a pair of vector registers without using memory.
+(define_predicate "easy_vector_pair_constant"
+  (match_code "const_vector")
+{
+  rtx hi_constant, lo_constant;
+  machine_mode vmode;
+
+  if (!TARGET_MMA || !TARGET_VECTOR_SIZE_32 || !VECTOR_PAIR_MODE (mode))
+    return false;
+
+  vmode = vector_pair_to_vector_mode (mode);
+  if (vmode == VOIDmode)
+    return false;
+
+  return (split_vector_pair_constant (op, &hi_constant, &lo_constant)
+	  && easy_vector_constant (hi_constant, vmode)
+	  && easy_vector_constant (lo_constant, vmode));
+})
+
 ;; Same as easy_vector_constant but only for EASY_VECTOR_15_ADD_SELF.
 (define_predicate "easy_vector_constant_add_self"
   (and (match_code "const_vector")
@@ -1301,8 +1329,10 @@  (define_predicate "splat_input_operand"
 
 ;; Return 1 if this operand is valid for a MMA assemble accumulator insn.
 (define_special_predicate "mma_assemble_input_operand"
-  (match_test "(mode == V16QImode
+  (match_test "(GET_MODE_SIZE (mode) == 16 && VECTOR_MODE_P (mode)
 		&& (vsx_register_operand (op, mode)
+		    || op == CONST0_RTX (mode)
+		    || vsx_prefixed_constant (op, mode)
 		    || (MEM_P (op)
 			&& (indexed_or_indirect_address (XEXP (op, 0), mode)
 			    || quad_address_p (XEXP (op, 0), mode, false)))))"))
diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
index 65be0ac43e2..27114b14022 100644
--- a/gcc/config/rs6000/rs6000-c.cc
+++ b/gcc/config/rs6000/rs6000-c.cc
@@ -631,6 +631,9 @@  rs6000_cpu_cpp_builtins (cpp_reader *pfile)
     builtin_define ("__SIZEOF_IBM128__=16");
   if (ieee128_float_type_node)
     builtin_define ("__SIZEOF_IEEE128__=16");
+  if (TARGET_MMA && TARGET_VECTOR_SIZE_32)
+    builtin_define ("__VECTOR_SIZE_32__");
+
 #ifdef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB
   builtin_define ("__BUILTIN_CPU_SUPPORTS__");
 #endif
diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h
index f70118ea40f..e17d73cb4ca 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -61,6 +61,9 @@  extern bool rs6000_move_128bit_ok_p (rtx []);
 extern bool rs6000_split_128bit_ok_p (rtx []);
 extern void rs6000_expand_float128_convert (rtx, rtx, bool);
 extern void rs6000_expand_vector_init (rtx, rtx);
+extern machine_mode vector_pair_to_vector_mode (machine_mode);
+extern bool split_vector_pair_constant (rtx, rtx *, rtx *);
+extern void rs6000_expand_vector_pair_init (rtx, rtx);
 extern void rs6000_expand_vector_set (rtx, rtx, rtx);
 extern void rs6000_expand_vector_extract (rtx, rtx, rtx);
 extern void rs6000_split_vec_extract_var (rtx, rtx, rtx, rtx, rtx);
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 0dd21e67dde..c9bd8c35e63 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -1843,7 +1843,7 @@  rs6000_hard_regno_mode_ok_uncached (int regno, machine_mode mode)
 
   /* Vector pair modes need even/odd VSX register pairs.  Only allow vector
      registers.  */
-  if (mode == OOmode)
+  if (VECTOR_PAIR_MODE (mode))
     return (TARGET_MMA && VSX_REGNO_P (regno) && (regno & 1) == 0);
 
   /* MMA accumulator modes need FPR registers divisible by 4.  */
@@ -1954,9 +1954,10 @@  rs6000_hard_regno_mode_ok (unsigned int regno, machine_mode mode)
    GPR registers, and TImode can go in any GPR as well as VSX registers (PR
    57744).
 
-   Similarly, don't allow OOmode (vector pair, restricted to even VSX
-   registers) or XOmode (vector quad, restricted to FPR registers divisible
-   by 4) to tie with other modes.
+   Similarly, don't allow XOmode (vector quad, restricted to FPR registers
+   divisible by 4) to tie with other modes.
+
+   Vector pair modes can tie with other vector pair modes.
 
    Altivec/VSX vector tests were moved ahead of scalar float mode, so that IEEE
    128-bit floating point on VSX systems ties with other vectors.  */
@@ -1964,9 +1965,14 @@  rs6000_hard_regno_mode_ok (unsigned int regno, machine_mode mode)
 static bool
 rs6000_modes_tieable_p (machine_mode mode1, machine_mode mode2)
 {
-  if (mode1 == PTImode || mode1 == OOmode || mode1 == XOmode
-      || mode2 == PTImode || mode2 == OOmode || mode2 == XOmode)
-    return mode1 == mode2;
+  if (mode1 == PTImode || mode1 == XOmode
+       || mode2 == PTImode || mode2 == XOmode)
+     return mode1 == mode2;
+ 
+  if (VECTOR_PAIR_MODE (mode1))
+    return VECTOR_PAIR_MODE (mode2);
+  if (VECTOR_PAIR_MODE (mode2))
+    return ALTIVEC_OR_VSX_VECTOR_MODE (mode1);
 
   if (ALTIVEC_OR_VSX_VECTOR_MODE (mode1))
     return ALTIVEC_OR_VSX_VECTOR_MODE (mode2);
@@ -2715,13 +2721,13 @@  rs6000_setup_reg_addr_masks (void)
 	     of the LXVP or STXVP instructions, do not allow indexed mode so
 	     that we can split the load/store.  */
 	  else if ((addr_mask != 0) && TARGET_MMA
-		   && (m2 == OOmode || m2 == XOmode))
+		   && (VECTOR_PAIR_MODE (m2) || m2 == XOmode))
 	    {
 	      addr_mask |= RELOAD_REG_OFFSET;
 	      if (rc == RELOAD_REG_FPR || rc == RELOAD_REG_VMX)
 		{
 		  addr_mask |= RELOAD_REG_QUAD_OFFSET;
-		  if (m2 == OOmode
+		  if (VECTOR_PAIR_MODE (m2)
 		      && TARGET_LOAD_VECTOR_PAIR
 		      && TARGET_STORE_VECTOR_PAIR)
 		    addr_mask |= RELOAD_REG_INDEXED;
@@ -2941,6 +2947,33 @@  rs6000_init_hard_regno_mode_ok (bool global_init_p)
       rs6000_vector_align[XOmode] = 512;
     }
 
+  if (TARGET_MMA && TARGET_VECTOR_SIZE_32)
+    {
+      rs6000_vector_unit[V32QImode] = VECTOR_NONE;
+      rs6000_vector_mem[V32QImode] = VECTOR_VSX;
+      rs6000_vector_align[V32QImode] = 256;
+
+      rs6000_vector_unit[V16HImode] = VECTOR_NONE;
+      rs6000_vector_mem[V16HImode] = VECTOR_VSX;
+      rs6000_vector_align[V16HImode] = 256;
+
+      rs6000_vector_unit[V8SImode] = VECTOR_NONE;
+      rs6000_vector_mem[V8SImode] = VECTOR_VSX;
+      rs6000_vector_align[V8SImode] = 256;
+
+      rs6000_vector_unit[V8SFmode] = VECTOR_NONE;
+      rs6000_vector_mem[V8SFmode] = VECTOR_VSX;
+      rs6000_vector_align[V8SFmode] = 256;
+
+      rs6000_vector_unit[V4DImode] = VECTOR_NONE;
+      rs6000_vector_mem[V4DImode] = VECTOR_VSX;
+      rs6000_vector_align[V4DImode] = 256;
+
+      rs6000_vector_unit[V4DFmode] = VECTOR_NONE;
+      rs6000_vector_mem[V4DFmode] = VECTOR_VSX;
+      rs6000_vector_align[V4DFmode] = 256;
+    }
+
   /* Register class constraints for the constraints that depend on compile
      switches. When the VSX code was added, different constraints were added
      based on the type (DFmode, V2DFmode, V4SFmode).  For the vector types, all
@@ -3072,6 +3105,22 @@  rs6000_init_hard_regno_mode_ok (bool global_init_p)
 		  reg_addr[XOmode].reload_store = CODE_FOR_reload_xo_di_store;
 		  reg_addr[XOmode].reload_load = CODE_FOR_reload_xo_di_load;
 		}
+
+	      if (TARGET_MMA && TARGET_VECTOR_SIZE_32)
+		{
+		  reg_addr[V32QImode].reload_store = CODE_FOR_reload_v32qi_di_store;
+		  reg_addr[V32QImode].reload_load = CODE_FOR_reload_v32qi_di_load;
+		  reg_addr[V16HImode].reload_store = CODE_FOR_reload_v16hi_di_store;
+		  reg_addr[V16HImode].reload_load = CODE_FOR_reload_v16hi_di_load;
+		  reg_addr[V8SImode].reload_store = CODE_FOR_reload_v8si_di_store;
+		  reg_addr[V8SImode].reload_load = CODE_FOR_reload_v8si_di_load;
+		  reg_addr[V8SFmode].reload_store = CODE_FOR_reload_v8sf_di_store;
+		  reg_addr[V8SFmode].reload_load = CODE_FOR_reload_v8sf_di_load;
+		  reg_addr[V4DImode].reload_store = CODE_FOR_reload_v4di_di_store;
+		  reg_addr[V4DImode].reload_load = CODE_FOR_reload_v4di_di_load;
+		  reg_addr[V4DFmode].reload_store = CODE_FOR_reload_v4df_di_store;
+		  reg_addr[V4DFmode].reload_load = CODE_FOR_reload_v4df_di_load;
+		}
 	    }
 	}
       else
@@ -3129,6 +3178,22 @@  rs6000_init_hard_regno_mode_ok (bool global_init_p)
 	      reg_addr[DDmode].reload_fpr_gpr = CODE_FOR_reload_fpr_from_gprdd;
 	      reg_addr[DFmode].reload_fpr_gpr = CODE_FOR_reload_fpr_from_gprdf;
 	    }
+
+	  if (TARGET_MMA && TARGET_VECTOR_SIZE_32)
+	    {
+	      reg_addr[V32QImode].reload_store = CODE_FOR_reload_v32qi_si_store;
+	      reg_addr[V32QImode].reload_load = CODE_FOR_reload_v32qi_si_load;
+	      reg_addr[V16HImode].reload_store = CODE_FOR_reload_v16hi_si_store;
+	      reg_addr[V16HImode].reload_load = CODE_FOR_reload_v16hi_si_load;
+	      reg_addr[V8SImode].reload_store = CODE_FOR_reload_v8si_si_store;
+	      reg_addr[V8SImode].reload_load = CODE_FOR_reload_v8si_si_load;
+	      reg_addr[V8SFmode].reload_store = CODE_FOR_reload_v8sf_si_store;
+	      reg_addr[V8SFmode].reload_load = CODE_FOR_reload_v8sf_si_load;
+	      reg_addr[V4DImode].reload_store = CODE_FOR_reload_v4di_si_store;
+	      reg_addr[V4DImode].reload_load = CODE_FOR_reload_v4di_si_load;
+	      reg_addr[V4DFmode].reload_store = CODE_FOR_reload_v4df_si_store;
+	      reg_addr[V4DFmode].reload_load = CODE_FOR_reload_v4df_si_load;
+	    }
 	}
 
       reg_addr[DFmode].scalar_in_vmx_p = true;
@@ -4429,6 +4494,15 @@  rs6000_option_override_internal (bool global_init_p)
       rs6000_isa_flags &= OPTION_MASK_STORE_VECTOR_PAIR;
     }
 
+  if (!TARGET_MMA && TARGET_VECTOR_SIZE_32)
+    {
+      if (OPTION_SET_P (TARGET_VECTOR_SIZE_32))
+	warning (0, "%qs should not be used unless you use %qs",
+		 "-mvector-size-32", "-mmma");
+
+      TARGET_VECTOR_SIZE_32 = 0;
+    }
+
   /* Enable power10 fusion if we are tuning for power10, even if we aren't
      generating power10 instructions.  */
   if (!(rs6000_isa_flags_explicit & OPTION_MASK_P10_FUSION))
@@ -7275,6 +7349,142 @@  rs6000_expand_vector_init (rtx target, rtx vals)
   emit_move_insn (target, mem);
 }
 
+/* For a vector pair mode, return the equivalent vector mode or VOIDmode.  */
+
+machine_mode
+vector_pair_to_vector_mode (machine_mode mode)
+{
+  machine_mode vmode;
+
+  switch (mode)
+    {
+    case E_V32QImode:  vmode = V16QImode; break;
+    case E_V16HImode:  vmode = V8HImode;  break;
+    case E_V8SImode:   vmode = V4SImode;  break;
+    case E_V4DImode:   vmode = V2DImode;  break;
+    case E_V8SFmode:   vmode = V4SFmode;  break;
+    case E_V4DFmode:   vmode = V2DFmode;  break;
+    case E_OOmode:     vmode = V1TImode;  break;
+    default:           vmode = VOIDmode;  break;
+    }
+
+  return vmode;
+}
+
+/* Split a vector constant for a type that can be held into a vector register
+   pair into 2 separate constants that can be held in a single vector register.
+   Return true if we can split the constant.  */
+
+bool
+split_vector_pair_constant (rtx op, rtx *high, rtx *low)
+{
+  machine_mode vmode = vector_pair_to_vector_mode (GET_MODE (op));
+
+  *high = *low = NULL_RTX;
+
+  if (!CONST_VECTOR_P (op) || vmode == GET_MODE (op))
+    return false;
+
+  size_t nunits = GET_MODE_NUNITS (vmode);
+  rtvec hi_vec = rtvec_alloc (nunits);
+  rtvec lo_vec = rtvec_alloc (nunits);
+
+  for (size_t i = 0; i < nunits; i++)
+    {
+      RTVEC_ELT (hi_vec, i) = CONST_VECTOR_ELT (op, i);
+      RTVEC_ELT (lo_vec, i) = CONST_VECTOR_ELT (op, i + nunits);
+    }
+
+  *high = gen_rtx_CONST_VECTOR (vmode, hi_vec);
+  *low = gen_rtx_CONST_VECTOR (vmode, lo_vec);
+  return true;
+}
+
+/* Initialize vector pair TARGET to VALS.  */
+
+void
+rs6000_expand_vector_pair_init (rtx target, rtx vals)
+{
+  machine_mode mode_vpair = GET_MODE (target);
+  machine_mode mode_vector;
+  size_t n_elts_vpair = GET_MODE_NUNITS (mode_vpair);
+  bool all_same = true;
+  rtx first = XVECEXP (vals, 0, 0);
+  rtx (*gen_splat) (rtx, rtx);
+  rtx (*gen_concat) (rtx, rtx, rtx);
+
+  switch (mode_vpair)
+    {
+    case E_V32QImode:
+      mode_vector = V16QImode;
+      gen_splat = gen_vpair_splat_v32qi;
+      gen_concat = gen_vpair_concat_v32qi;
+      break;
+
+    case E_V16HImode:
+      mode_vector = V8HImode;
+      gen_splat = gen_vpair_splat_v16hi;
+      gen_concat = gen_vpair_concat_v16hi;
+      break;
+
+    case E_V8SImode:
+      mode_vector = V4SImode;
+      gen_splat = gen_vpair_splat_v8si;
+      gen_concat = gen_vpair_concat_v8si;
+      break;
+
+    case E_V4DImode:
+      mode_vector = V2DImode;
+      gen_splat = gen_vpair_splat_v4di;
+      gen_concat = gen_vpair_concat_v4di;
+      break;
+
+    case E_V8SFmode:
+      mode_vector = V4SFmode;
+      gen_splat = gen_vpair_splat_v8sf;
+      gen_concat = gen_vpair_concat_v8sf;
+      break;
+
+    case E_V4DFmode:
+      mode_vector = V2DFmode;
+      gen_splat = gen_vpair_splat_v4df;
+      gen_concat = gen_vpair_concat_v4df;
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  /* See if we can do a splat operation.  */
+  for (size_t i = 1; i < n_elts_vpair; ++i)
+    {
+      if (!rtx_equal_p (XVECEXP (vals, 0, i), first))
+	{
+	  all_same = false;
+	  break;
+	}
+    }
+
+  if (all_same)
+    {
+      emit_insn (gen_splat (target, first));
+      return;
+    }
+
+  /* Break the initialization into two parts.  */
+  rtx vector_hi = gen_reg_rtx (mode_vector);
+  rtx vector_lo = gen_reg_rtx (mode_vector);
+  rtx vals_hi;
+  rtx vals_lo;
+
+  split_vector_pair_constant (vals, &vals_hi, &vals_lo);
+
+  rs6000_expand_vector_init (vector_hi, vals_hi);
+  rs6000_expand_vector_init (vector_lo, vals_lo);
+  emit_insn (gen_concat (target, vector_hi, vector_lo));
+  return;
+}
+
 /* Insert VAL into IDX of TARGET, VAL size is same of the vector element, IDX
    is variable and also counts by vector element size for p9 and above.  */
 
@@ -8694,6 +8904,12 @@  reg_offset_addressing_ok_p (machine_mode mode)
       /* The vector pair/quad types support offset addressing if the
 	 underlying vectors support offset addressing.  */
     case E_OOmode:
+    case E_V32QImode:
+    case E_V16HImode:
+    case E_V8SImode:
+    case E_V8SFmode:
+    case E_V4DImode:
+    case E_V4DFmode:
     case E_XOmode:
       return TARGET_MMA;
 
@@ -11202,6 +11418,12 @@  rs6000_emit_move (rtx dest, rtx source, machine_mode mode)
     case E_V2DFmode:
     case E_V2DImode:
     case E_V1TImode:
+    case E_V32QImode:
+    case E_V16HImode:
+    case E_V8SFmode:
+    case E_V8SImode:
+    case E_V4DFmode:
+    case E_V4DImode:
       if (CONSTANT_P (operands[1])
 	  && !easy_vector_constant (operands[1], mode))
 	operands[1] = force_const_mem (mode, operands[1]);
@@ -13456,7 +13678,7 @@  rs6000_preferred_reload_class (rtx x, enum reg_class rclass)
      the GPR registers.  */
   if (rclass == GEN_OR_FLOAT_REGS)
     {
-      if (mode == OOmode)
+      if (VECTOR_PAIR_MODE (mode))
 	return VSX_REGS;
 
       if (mode == XOmode)
@@ -23417,6 +23639,7 @@  altivec_expand_vec_perm_le (rtx operands[4])
   rtx tmp = target;
   rtx norreg = gen_reg_rtx (V16QImode);
   machine_mode mode = GET_MODE (target);
+  machine_mode qi_vmode = VECTOR_PAIR_MODE (mode) ? V32QImode : V16QImode;
 
   /* Get everything in regs so the pattern matches.  */
   if (!REG_P (op0))
@@ -23424,7 +23647,7 @@  altivec_expand_vec_perm_le (rtx operands[4])
   if (!REG_P (op1))
     op1 = force_reg (mode, op1);
   if (!REG_P (sel))
-    sel = force_reg (V16QImode, sel);
+    sel = force_reg (qi_vmode, sel);
   if (!REG_P (target))
     tmp = gen_reg_rtx (mode);
 
@@ -23437,10 +23660,10 @@  altivec_expand_vec_perm_le (rtx operands[4])
     {
       /* Invert the selector with a VNAND if available, else a VNOR.
 	 The VNAND is preferred for future fusion opportunities.  */
-      notx = gen_rtx_NOT (V16QImode, sel);
+      notx = gen_rtx_NOT (qi_vmode, sel);
       iorx = (TARGET_P8_VECTOR
-	      ? gen_rtx_IOR (V16QImode, notx, notx)
-	      : gen_rtx_AND (V16QImode, notx, notx));
+	      ? gen_rtx_IOR (qi_vmode, notx, notx)
+	      : gen_rtx_AND (qi_vmode, notx, notx));
       emit_insn (gen_rtx_SET (norreg, iorx));
 
       /* Permute with operands reversed and adjusted selector.  */
@@ -24572,6 +24795,9 @@  static struct rs6000_opt_var const rs6000_opt_vars[] =
   { "speculate-indirect-jumps",
     offsetof (struct gcc_options, x_rs6000_speculate_indirect_jumps),
     offsetof (struct cl_target_option, x_rs6000_speculate_indirect_jumps), },
+  { "vector-size-32",
+    offsetof (struct gcc_options, x_TARGET_VECTOR_SIZE_32),
+    offsetof (struct cl_target_option, x_TARGET_VECTOR_SIZE_32), },
 };
 
 /* Inner function to handle attribute((target("..."))) and #pragma GCC target
@@ -27426,6 +27652,8 @@  rs6000_split_multireg_move (rtx dst, rtx src)
   int reg_mode_size;
   /* The number of registers that will be moved.  */
   int nregs;
+  /* Hi/lo values for splitting vector pair constants.  */
+  rtx vpair_hi, vpair_lo;
 
   reg = REG_P (dst) ? REGNO (dst) : REGNO (src);
   mode = GET_MODE (dst);
@@ -27441,8 +27669,11 @@  rs6000_split_multireg_move (rtx dst, rtx src)
     }
   /* If we have a vector pair/quad mode, split it into two/four separate
      vectors.  */
-  else if (mode == OOmode || mode == XOmode)
-    reg_mode = V1TImode;
+  else if (VECTOR_PAIR_MODE (mode) || mode == XOmode)
+    {
+      machine_mode vmode = vector_pair_to_vector_mode (mode);
+      reg_mode = (vmode == VOIDmode) ? V1TImode : vmode;
+    }
   else if (FP_REGNO_P (reg))
     reg_mode = DECIMAL_FLOAT_MODE_P (mode) ? DDmode :
 	(TARGET_HARD_FLOAT ? DFmode : SFmode);
@@ -27454,6 +27685,29 @@  rs6000_split_multireg_move (rtx dst, rtx src)
 
   gcc_assert (reg_mode_size * nregs == GET_MODE_SIZE (mode));
 
+  /* Handle vector pair constants.  */
+  if (CONST_VECTOR_P (src) && VECTOR_PAIR_MODE (mode) && TARGET_MMA
+      && split_vector_pair_constant (src, &vpair_hi, &vpair_lo)
+      && VSX_REGNO_P (reg))
+    {
+      reg_mode = GET_MODE (vpair_hi);
+      rtx reg_hi = gen_rtx_REG (reg_mode, reg);
+      rtx reg_lo = gen_rtx_REG (reg_mode, reg + 1);
+
+      emit_move_insn (reg_hi, vpair_hi);
+
+      /* 0.0 is easy.  For other constants, copy the high register into the low
+	 register if the two sets of constants are equal.  This means we won't
+	 be doing back to back prefixed load immediate instructions.  */
+      if (rtx_equal_p (vpair_hi, vpair_lo)
+	  && !rtx_equal_p (vpair_hi, CONST0_RTX (reg_mode)))
+	emit_move_insn (reg_lo, reg_hi);
+      else
+	emit_move_insn (reg_lo, vpair_lo);
+      
+      return;
+    }
+      
   /* TDmode residing in FP registers is special, since the ISA requires that
      the lower-numbered word of a register pair is always the most significant
      word, even in little-endian mode.  This does not match the usual subreg
@@ -27493,7 +27747,7 @@  rs6000_split_multireg_move (rtx dst, rtx src)
      below.  This means the last register gets the first memory
      location.  We also need to be careful of using the right register
      numbers if we are splitting XO to OO.  */
-  if (mode == OOmode || mode == XOmode)
+  if (VECTOR_PAIR_MODE (mode) || mode == XOmode)
     {
       nregs = hard_regno_nregs (reg, mode);
       int reg_mode_nregs = hard_regno_nregs (reg, reg_mode);
@@ -27553,7 +27807,7 @@  rs6000_split_multireg_move (rtx dst, rtx src)
 	  gcc_assert (REG_P (dst));
 	  if (GET_MODE (src) == XOmode)
 	    gcc_assert (FP_REGNO_P (REGNO (dst)));
-	  if (GET_MODE (src) == OOmode)
+	  if (VECTOR_PAIR_MODE (GET_MODE (src)))
 	    gcc_assert (VSX_REGNO_P (REGNO (dst)));
 
 	  int nvecs = XVECLEN (src, 0);
@@ -27628,7 +27882,7 @@  rs6000_split_multireg_move (rtx dst, rtx src)
 	 overlap.  */
       int i;
       /* XO/OO are opaque so cannot use subregs. */
-      if (mode == OOmode || mode == XOmode )
+      if (VECTOR_PAIR_MODE (mode) || mode == XOmode )
 	{
 	  for (i = nregs - 1; i >= 0; i--)
 	    {
@@ -27802,7 +28056,7 @@  rs6000_split_multireg_move (rtx dst, rtx src)
 	    continue;
 
 	  /* XO/OO are opaque so cannot use subregs. */
-	  if (mode == OOmode || mode == XOmode )
+	  if (VECTOR_PAIR_MODE (mode) || mode == XOmode )
 	    {
 	      rtx dst_i = gen_rtx_REG (reg_mode, REGNO (dst) + j);
 	      rtx src_i = gen_rtx_REG (reg_mode, REGNO (src) + j);
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 326c45221e9..32848f7d15b 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -1006,6 +1006,12 @@  enum data_align { align_abi, align_opt, align_both };
   (ALTIVEC_VECTOR_MODE (MODE) || VSX_VECTOR_MODE (MODE)			\
    || (MODE) == V2DImode || (MODE) == V1TImode)
 
+/* Whether a mode is held in paired vector registers.  */
+#define VECTOR_PAIR_MODE(MODE)						\
+  ((MODE) == OOmode							\
+   || (MODE) == V32QImode || (MODE) == V16HImode || (MODE) == V8SImode	\
+   || (MODE) == V4DImode || (MODE) == V8SFmode || (MODE) == V4DFmode)
+
 /* Post-reload, we can't use any new AltiVec registers, as we already
    emitted the vrsave mask.  */
 
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index dcf1f3526f5..e9f2244c216 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -683,9 +683,13 @@  (define_mode_attr wd [(QI    "b")
 		      (HI    "h")
 		      (SI    "w")
 		      (DI    "d")
+		      (V32QI "b")
 		      (V16QI "b")
+		      (V16HI "h")
 		      (V8HI  "h")
+		      (V8SI  "w")
 		      (V4SI  "w")
+		      (V4DI  "d")
 		      (V2DI  "d")
 		      (V1TI  "q")
 		      (TI    "q")])
@@ -812,7 +816,7 @@  (define_mode_attr BOOL_REGS_UNARY	[(TI	"r,0,0,wa,v")
 ;; supplement addressing modes.
 (define_mode_iterator RELOAD [V16QI V8HI V4SI V2DI V4SF V2DF V1TI
 			      SF SD SI DF DD DI TI PTI KF IF TF
-			      OO XO])
+			      OO XO V32QI V16HI V8SI V8SF V4DI V4DF])
 
 ;; Iterate over smin, smax
 (define_code_iterator fp_minmax	[smin smax])
@@ -15767,6 +15771,7 @@  (define_insn "hashchk"
 (include "vsx.md")
 (include "altivec.md")
 (include "mma.md")
+(include "vector-pair.md")
 (include "dfp.md")
 (include "crypto.md")
 (include "htm.md")
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 369095df9ed..bc2966f6120 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -605,6 +605,10 @@  mstore-vector-pair
 Target Undocumented Mask(STORE_VECTOR_PAIR) Var(rs6000_isa_flags)
 Generate (do not generate) store vector pair instructions.
 
+mvector-size-32
+Target Undocumented Var(TARGET_VECTOR_SIZE_32) Init(0) Save
+Generate (do not generate) vector pair instructions for vector_size(32).
+
 mrelative-jumptables
 Target Undocumented Var(rs6000_relative_jumptables) Init(1) Save
 
diff --git a/gcc/config/rs6000/vector-pair.md b/gcc/config/rs6000/vector-pair.md
new file mode 100644
index 00000000000..068f562200a
--- /dev/null
+++ b/gcc/config/rs6000/vector-pair.md
@@ -0,0 +1,319 @@ 
+;; Vector pair arithmetic and logical instruction support.
+;; Copyright (C) 2020-2023 Free Software Foundation, Inc.
+;; Contributed by Peter Bergner <bergner@linux.ibm.com> and
+;;		  Michael Meissner <meissner@linux.ibm.com>
+;;
+;; This file is part of GCC.
+;;
+;; GCC is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published
+;; by the Free Software Foundation; either version 3, or (at your
+;; option) any later version.
+;;
+;; GCC is distributed in the hope that it will be useful, but WITHOUT
+;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+;; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+;; License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with GCC; see the file COPYING3.  If not see
+;; <http://www.gnu.org/licenses/>.
+
+;; This function adds support for doing vector operations on pairs of vector
+;; registers.  Most of the instructions use vector pair instructions to load
+;; and possibly store registers, but splitting the operation after register
+;; allocation to do 2 separate operations.  The second scheduler pass can
+;; interleave other instructions between these pairs of instructions if
+;; possible.
+
+;; Iterator for all vector pair modes.  Even though we do not provide integer
+;; vector pair operations at this time, we need to support loading and storing
+;; integer vector pairs for perumte operations (and eventually compare).
+(define_mode_iterator VPAIR [V32QI V16HI V8SI V4DI V8SF V4DF])
+
+;; Iterator for vector pairs with double word elements
+(define_mode_iterator VPAIR_DWORD [V4DI V4DF])
+
+;; Map vector pair mode to vector mode in upper case after the vector pair is
+;; split to two vectors.
+(define_mode_attr VPAIR_VECTOR [(V32QI "V16QI")
+				(V16HI "V8HI")
+				(V8SI  "V4SI")
+				(V4DI  "V2DI")
+				(V8SF  "V4SF")
+                                (V4DF  "V2DF")])
+
+;; Map vector pair mode to vector mode in lower case after the vector pair is
+;; split to two vectors.
+(define_mode_attr vpair_vector_l [(V32QI "v16qi")
+				  (V16HI "v8hi")
+				  (V8SI  "v4si")
+				  (V4DI  "v2di")
+				  (V8SF  "v4sf")
+				  (V4DF  "v2df")])
+
+;; Map vector pair mode to the base element mode.
+(define_mode_attr VPAIR_ELEMENT [(V32QI "QI")
+				 (V16HI "HI")
+				 (V8SI  "SI")
+				 (V4DI  "DI")
+				 (V8SF  "SF")
+				 (V4DF  "DF")])
+
+;; Map vector pair mode to the base element mode in lower case.
+(define_mode_attr vpair_element_l [(V32QI "qi")
+				   (V16HI "hi")
+				   (V8SI  "si")
+				   (V4DI  "di")
+				   (V8SF  "sf")
+				   (V4DF  "df")])
+
+;; Vector pair move support.
+(define_expand "mov<mode>"
+  [(set (match_operand:VPAIR 0 "nonimmediate_operand")
+	(match_operand:VPAIR 1 "input_operand"))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+{
+  rs6000_emit_move (operands[0], operands[1], <MODE>mode);
+  DONE;
+})
+
+(define_insn_and_split "*mov<mode>"
+  [(set (match_operand:VPAIR 0 "nonimmediate_operand"
+				"=wa, wa,   ZwO, QwO, wa, wa, wa")
+
+	(match_operand:VPAIR 1 "input_operand"
+				"ZwO,  QwO, wa,  wa,  wa, j,  eV"))]
+  "TARGET_MMA
+   && (gpc_reg_operand (operands[0], <MODE>mode)
+       || gpc_reg_operand (operands[1], <MODE>mode))"
+  "@
+   lxvp%X1 %x0,%1
+   #
+   stxvp%X0 %x1,%0
+   #
+   #
+   #
+   #"
+  "&& reload_completed
+   && ((MEM_P (operands[0]) && !TARGET_STORE_VECTOR_PAIR)
+       || (MEM_P (operands[1]) && !TARGET_LOAD_VECTOR_PAIR)
+       || (!MEM_P (operands[0]) && !MEM_P (operands[1])))"
+  [(const_int 0)]
+{
+  rs6000_split_multireg_move (operands[0], operands[1]);
+  DONE;
+}
+  [(set_attr "size" "256")
+   (set_attr "type"   "vecload, vecload, vecstore, vecstore, veclogical,
+                       vecperm, vecperm")
+   (set_attr "length" "*,       8,       *,        8,        8,
+                       8,       24")
+   (set_attr "isa"    "lxvp,    *,       stxvp,    *,        *,
+                       *,       *")])
+
+;; Vector pair initialization
+(define_expand "vec_init<mode><vpair_element_l>"
+  [(match_operand:VPAIR 0 "vsx_register_operand")
+   (match_operand:VPAIR 1 "")]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+{
+  rs6000_expand_vector_pair_init (operands[0], operands[1]);
+  DONE;
+})
+
+;; Set an element in a vector pair with double word elements.
+(define_insn_and_split "vec_set<mode>"
+  [(set (match_operand:VPAIR_DWORD 0 "vsx_register_operand" "+&wa")
+	(unspec:VPAIR_DWORD
+	 [(match_dup 0)
+	  (match_operand:<VPAIR_ELEMENT> 1 "vsx_register_operand" "wa")
+	  (match_operand 2 "const_0_to_3_operand" "n")]
+	 UNSPEC_VSX_SET))
+   (clobber (match_scratch:<VPAIR_ELEMENT> 3 "=&wa"))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+  "#"
+  "&& reload_completed"
+  [(const_int 0)]
+{
+  rtx dest = operands[0];
+  rtx value = operands[1];
+  HOST_WIDE_INT elt = INTVAL (operands[2]);
+  rtx tmp = operands[3];
+  machine_mode mode = <MODE>mode;
+  machine_mode vmode = <VPAIR_VECTOR>mode;
+  unsigned vsize = GET_MODE_SIZE (<VPAIR_VECTOR>mode);
+  unsigned reg_num = ((WORDS_BIG_ENDIAN && elt >= vsize)
+		      || (!WORDS_BIG_ENDIAN && elt < vsize));
+	   
+  rtx vreg = simplify_gen_subreg (vmode, dest, mode, reg_num * 16);
+
+  if ((elt & 0x1) == 0)
+    {
+      emit_insn (gen_vsx_extract_<vpair_vector_l> (tmp, vreg, const1_rtx));
+      emit_insn (gen_vsx_concat_<vpair_vector_l> (vreg, value, tmp));
+    }
+  else
+    {
+      emit_insn (gen_vsx_extract_<vpair_vector_l> (tmp, vreg, const0_rtx));
+      emit_insn (gen_vsx_concat_<vpair_vector_l> (vreg, tmp, value));
+    }
+
+  DONE;
+}
+  [(set_attr "length" "8")
+   (set_attr "type" "vecperm")])
+
+;; Exctract DF/DI from V4DF/V4DI, convert it into extract from V2DF/V2DI.
+(define_insn_and_split "vec_extract<mode><vpair_element_l>"
+  [(set (match_operand:<VPAIR_ELEMENT> 0 "gpc_reg_operand" "=wa,r")
+	(vec_select:<VPAIR_ELEMENT>
+	 (match_operand:VPAIR_DWORD 1 "gpc_reg_operand" "wa,wa")
+	 (parallel
+	  [(match_operand:QI 2 "const_0_to_3_operand" "n,n")])))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 0)
+	(vec_select:<VPAIR_ELEMENT>
+	 (match_dup 3)
+	 (parallel [(match_dup 4)])))]
+{
+  machine_mode vmode = <VPAIR_VECTOR>mode;
+  rtx op1 = operands[1];
+  HOST_WIDE_INT element = INTVAL (operands[2]);
+  unsigned reg_num = 0;
+
+  if ((WORDS_BIG_ENDIAN && element >= 2)
+      || (!WORDS_BIG_ENDIAN && element < 2))
+    reg_num++;
+
+  operands[3] = simplify_gen_subreg (vmode, op1, <MODE>mode, reg_num * 16);
+  operands[4] = GEN_INT (element & 1);
+}
+  [(set_attr "type" "mfvsr,vecperm")])
+
+;; Extract a SFmode element from V8SF
+(define_insn_and_split "vec_extractv8sfsf"
+  [(set (match_operand:SF 0 "vsx_register_operand" "=wa")
+	(vec_select:SF
+	 (match_operand:V8SF 1 "vsx_register_operand" "wa")
+	 (parallel [(match_operand:QI 2 "const_0_to_7_operand" "n")])))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+  "#"
+  "&& reload_completed"
+  [(const_int 0)]
+{
+  rtx op0 = operands[0];
+  rtx op1 = operands[1];
+  rtx tmp;
+  HOST_WIDE_INT element = INTVAL (operands[2]);
+  unsigned reg_num = 0;
+
+  if ((WORDS_BIG_ENDIAN && element >= 4)
+      || (!WORDS_BIG_ENDIAN && element < 4))
+    reg_num++;
+
+  rtx vreg = simplify_gen_subreg (V4SFmode, op1, V8SFmode, reg_num * 16);
+  HOST_WIDE_INT vreg_elt = element & 3;
+
+  /* Get the element into position 0 if it isn't there already.  */
+  if (!vreg_elt)
+    tmp = vreg;
+  else
+    {
+      tmp = gen_rtx_REG (V4SFmode, reg_or_subregno (op0));
+      emit_insn (gen_vsx_xxsldwi_v4sf (tmp, vreg, vreg, GEN_INT (vreg_elt)));
+    }
+
+  /* Convert the float element to double precision.  */
+  emit_insn (gen_vsx_xscvspdp_scalar2 (op0, tmp));
+  DONE;
+}
+  [(set_attr "length" "8")
+   (set_attr "type" "fp")])
+
+;; Assemble a vector pair from two vectors.
+;;
+;; We have both endian versions to change which input register will be moved
+;; the the first register in the vector pair.
+(define_expand "vpair_concat_<mode>"
+  [(set (match_operand:VPAIR 0 "vsx_register_operand")
+	(vec_concat:VPAIR
+	 (match_operand:<VPAIR_VECTOR> 1 "input_operand")
+	 (match_operand:<VPAIR_VECTOR> 2 "input_operand")))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32")
+
+(define_insn_and_split "*vpair_concat_<mode>_be"
+  [(set (match_operand:VPAIR 0 "vsx_register_operand" "=wa,&wa")
+	(vec_concat:VPAIR
+	 (match_operand:<VPAIR_VECTOR> 1 "input_operand" "0,mwajeP")
+	 (match_operand:<VPAIR_VECTOR> 2 "input_operand" "mwajeP,mwajeP")))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32 && WORDS_BIG_ENDIAN"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3) (match_dup 1))
+   (set (match_dup 4) (match_dup 2))]
+{
+  machine_mode vmode = <VPAIR_VECTOR>mode;
+  rtx op0 = operands[0];
+  operands[3] = simplify_gen_subreg (vmode, op0, <MODE>mode, 0);
+  operands[4] = simplify_gen_subreg (vmode, op0, <MODE>mode, 16);
+}
+  [(set_attr "length" "8")])
+
+(define_insn_and_split "*vpair_concat_<mode>_le"
+  [(set (match_operand:VPAIR 0 "vsx_register_operand" "=&wa,wa")
+	(vec_concat:VPAIR
+	 (match_operand:<VPAIR_VECTOR> 1 "input_operand" "mwajeP,0")
+	 (match_operand:<VPAIR_VECTOR> 2 "input_operand" "mwajeP,mwajeP")))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32 && !WORDS_BIG_ENDIAN"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3) (match_dup 1))
+   (set (match_dup 4) (match_dup 2))]
+{
+  machine_mode vmode = <VPAIR_VECTOR>mode;
+  rtx op0 = operands[0];
+  operands[3] = simplify_gen_subreg (vmode, op0, <MODE>mode, 0);
+  operands[4] = simplify_gen_subreg (vmode, op0, <MODE>mode, 16);
+}
+  [(set_attr "length" "8")])
+
+;; Zero a vector pair
+(define_expand "vpair_zero_<mode>"
+  [(set (match_operand:VPAIR 0 "vsx_register_operand") (match_dup 1))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+{
+  operands[1] = CONST0_RTX (<MODE>mode);
+})
+
+;; Create a vector pair with a value splat'ed (duplicated) to all of the
+;; elements.
+(define_expand "vpair_splat_<mode>"
+  [(use (match_operand:VPAIR 0 "vsx_register_operand"))
+   (use (match_operand:<VPAIR_ELEMENT> 1 "input_operand"))]
+  "TARGET_MMA && TARGET_VECTOR_SIZE_32"
+{
+  machine_mode vmode = <VPAIR_VECTOR>mode;
+  rtx op0 = operands[0];
+  rtx op1 = operands[1];
+
+  if (op1 == CONST0_RTX (vmode))
+    {
+      emit_insn (gen_vpair_zero_<mode> (op0));
+      DONE;
+    }
+
+  rtx tmp = gen_reg_rtx (vmode);
+
+  unsigned num_elements = GET_MODE_NUNITS (vmode);
+  rtvec elements = rtvec_alloc (num_elements);
+  for (size_t i = 0; i < num_elements; i++)
+    RTVEC_ELT (elements, i) = copy_rtx (op1);
+
+  rtx vec_elements = gen_rtx_PARALLEL (vmode, elements);
+  rs6000_expand_vector_init (tmp, vec_elements);
+  emit_insn (gen_vpair_concat_<mode> (op0, tmp, tmp));
+  DONE;
+})
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index e01cdcbe22c..23c151f90de 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -3509,6 +3509,10 @@  loaded to a VSX register with one prefixed instruction.
 An IEEE 128-bit constant that can be loaded into a VSX register with
 the @code{lxvkq} instruction.
 
+@item eV
+A vector pair constant that can be loaded to a VSX register with two
+separate instructions.
+
 @ifset INTERNALS
 @item G
 A floating point constant that can be loaded into a register with one